Abstract: R18.00005 : Rijke tube with flexible walls

Authors:

Shreyas Mandre(Brown University)

Bao-Nhat Nguyen(Brown University)

Marvin Li(Brown University)

Sound is excited spontaneously in a Rijke tube because the small
temperature perturbations in an acoustic field interact with heat
transfer from a heat source in the tube. The air particles near
the heat source undergo a thermodynamic cyle converting heat to
mechanical energy, which is heard as the sound emanating from the
Rijke tube. This principle of energy conversion is used in
thermoacoustic engines, and the main objective of this study is
to improve their performance.
The acoustic oscillations in the Rijke tube regulate the
thermodynamic cycle, just as in conventional engines the cycle is
controlled by the motion of a piston and the action of inlet and
exit valves. The acoustic regulation in the Rijke tube, however,
does not allow arbitrary control of the cycle in thermodynamic
phase space. In this presentation, we introduce a new way of
overcoming this limitation, one by using Rijke tubes with
flexible walls. We will discuss how this modification allows for
more general thermodynamic cycles to be executed by the air
particles in the tube. This possibility, when used in
thermoacoustic engines, opens a channel for further improving the
engine performance.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2011.DFD.R18.5